The GMT800 was a

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

full-size truck platform used from the 1999 through 2006 model years. It is the foundation for the

Chevrolet Silverado The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long running Chevrolet C/K model line. Taking its name from th ...

and GMC Sierra pickups; and the derivative GMT820 and GMT830 versions for the

Chevrolet Tahoe The Chevrolet Tahoe, and its badge engineered GMC Yukon counterpart, are full-size SUVs from General Motors, offered since 1994 and 1991, respectively. Since 1982, Chevrolet and GMC sold two different-sized SUVs under their 'Blazer' and 'Jimmy ...

/GMC Yukon and the

Chevrolet Suburban The Chevrolet Suburban is a series of automobiles built by the Chevrolet division of General Motors. The name started in 1934 for the 1935 U.S. model year, making it the longest continuously used automobile nameplate in production. It has tra ...

/GMC Yukon XL full-size SUVs, respectively. This platform was the successor to the

GMT400 The GMT 400 and similar GMT 480 was the platform for the 1988-1998 model year Chevrolet C/K / GMC Sierra full-size pickup trucks. The GMT 410, GMT 420, GMT 425, and GMT 430 were derived for full-size SUVs, including the 1992–1994 Chevrolet Bl ...

series of C/K pickups and SUVs, and was replaced for 2007 by the

GMT900 The GMT900 was a General Motors full-size pickup and SUV platform used for the 2007 to 2014 model years. The platform was introduced at the 2006 North American International Auto Show, as the replacement for the GMT800 platform. The first GMT90 ...

line. The GMT800 frames were manufactured by

Magna International Magna International Inc. is a Canadian parts manufacturer for automakers. It is one of the largest companies in Canada and was recognized on the 2020 ''Forbes'' Global 2000. The company is the largest automobile parts manufacturer in North Ameri ...

Ramos Arizpe Ramos Arizpe () is a city and seat of the surrounding municipality of the same name in the Mexican state of Coahuila. Ramos Arizpe is located 11 km from the state capital of Saltillo. It is part of the Saltillo metropolitan area. The city ...

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

and St. Thomas, Ontario, Canada. Trucks were assembled in

Oshawa, Ontario Oshawa ( , also ; 2021 population 175,383; CMA 415,311) is a city in Ontario, Canada, on the Lake Ontario shoreline. It lies in Southern Ontario, approximately east of Downtown Toronto. It is commonly viewed as the eastern anchor of the Gr ...

;

Pontiac, Michigan Pontiac ( ') is a city in and the county seat of Oakland County in the U.S. state of Michigan. As of the 2020 census, the city had a total population of 61,606. A northern suburb of Metro Detroit, Pontiac is about northwest of Detroit. Founde ...

;

Fort Wayne, Indiana Fort Wayne is a city in and the county seat of Allen County, Indiana, United States. Located in northeastern Indiana, the city is west of the Ohio border and south of the Michigan border. The city's population was 263,886 as of the 2020 Censu ...

; and

Flint, Michigan Flint is the largest city and seat of Genesee County, Michigan, United States. Located along the Flint River, northwest of Detroit, it is a principal city within the region known as Mid Michigan. At the 2020 census, Flint had a population of 8 ...

; for pickup & chassis cab models, and

Silao, Mexico Silao (), officially Silao de la Victoria, is a city in the west-central part of the state of Guanajuato in Mexico. It is the seat of the municipality with the same name. As of the 2005 census, the city had a population of 147,123, making it the ...

;

Janesville, Wisconsin Janesville is a city in Rock County, Wisconsin, United States. It is the county seat and largest city in the county. It is a principal municipality of the Janesville, Wisconsin, Metropolitan Statistical Area and is included in the Madison–Jan ...

; and

Arlington, Texas Arlington is a city in the U.S. state of Texas, located in Tarrant County. It forms part of the Mid-Cities region of the Dallas–Fort Worth–Arlington metropolitan statistical area, and is a principal city of the metropolis and region. ...

; for SUV models. The GMT820-based

Hummer H2 The Hummer H2 is a large SUV that was marketed by Hummer and built in the AM General facility under contract from General Motors from 2002 to 2009. It is based on a modified GMT820 GM three-quarter-ton pickup truck in the front and a half-ton 1 ...

was built under contract by

AM General AM General is an American heavy vehicle and contract automotive manufacturer based in South Bend, Indiana. It is best known for the civilian Hummer and the military Humvee that are assembled in Mishawaka, Indiana. For a relatively brief period, ...

at a specially-constructed plant in

Mishawaka, Indiana Mishawaka is a city on the St. Joseph River, in Penn Township, St. Joseph County, in the U.S. state of Indiana. The population was 51,063 as of the 2020 census. Its nickname is "the Princess City". Mishawaka is a principal city of the South ...

. A GMT810 2 door SUV variant was designed and prototyped, but was not put into production. The GMT800 introduced a three-section frame system. This could be mixed and matched depending on the wheelbase,

GVWR Vehicle weight is a measurement of wheeled motor vehicles; either an actual measured weight of the vehicle under defined conditions or a gross weight rating for its weight carrying capacity. Curb or kerb weight Curb weight (U.S. English) or kerb ...

, and body type fitted to the platform, rather than a single-piece long frame. The front section was hydroformed, while the middle and rear sections were roll formed or stamped, depending on application. This gives greater flexibility to the platform. A total of four front modules, seven midsections, and four rear sections were designed, and supported nearly 40 truck configurations. The GMT800 pickup models used a rear-leaf spring suspension, while the GMT820/830 SUV models used a five-link coil-spring suspension. (The 2500 series GMT830 SUV models retained a leaf spring suspension.) The GMT800 was the first truck application for the then-new GM Generation III V8 engines. The 4.8 L and 5.3 L versions used iron blocks and aluminum heads, while early 6.0 L version used cast iron cylinder heads. The 6.6 L Duramax turbo-diesel was introduced with the 2500, 2500HD, and 3500 models that debuted for 2001. The GMT800 1500 Chevrolet Silverado was named the MotorTrend Truck of the Year for 1999, the 2500 HD was awarded Truck of the Year for 2001, and the Chevrolet Avalanche was the Truck of the Year for 2002. Truck of the Year
Motor Trend

Sales

Applications

File:2003_Cadillac_Escalade_EXT.JPG, 2003 GMT800 Cadillac Escalade EXT File:2006_Chevrolet_Silverado_Extended_Cab.jpg, 2006 GMT800 Chevrolet Silverado File:2004_GMC_Yukon.jpg, 2004 GMT800 GMC Yukon File:2002_GMC_Sierra.jpg, 2002 GMT800 GMC Sierra

References

{{reflist General Motors platforms

Sales

Applications

See also

References